Submerged cultivation of Agaricus bisporus: An alternate approach to utilize corn steep liquor and defatted soya flour to produce novel food

Abstract

This study explores the sustainable cultivation of Agaricus bisporus mycelia using agro-industrial byproducts i.e., corn steep liquor (CSL) and defatted soy flour (DSF) as substrates under submerged fermentation. Preliminary plate study revealed that CSL and DSF supported A. bisporus growth comparable to potato dextrose agar (PDA). Screening of carbon-to‑nitrogen (C/N) ratio revealed a C/N ratio of 14 as favorable, with CSL at 25.0 g/L and DSF at 14.2 g/L selected for the initial media formulations. However, DSF at 14.2 g/L formed lumps post-autoclaving, necessitating the development of a combined CSL + DSF medium containing 7.5 g/L of each substrate. This formulation achieved a biomass productivity of 0.066 ± 0.002 g/L.h, surpassing the productivity in CSL media (0.052 ± 0.001 g/L.h). Scale-up studies in fermenter demonstrated slightly reduced productivity of 0.062 ± 0.001 g/L.h with CSL + DSF medium. UVB irradiation of the mycelium significantly increased vitamin D2 content (28.69 μg/g dry mass), surpassing levels in UV-irradiated fruiting bodies (15.45 μg/g dry mass). Nutritional analysis reveals that the cultivated mycelium is rich in protein, fat, and essential minerals (Zn, Fe, Mg, K, Ca, Co, Cu, and Mn), with β-D-glucan content comparable to that of the fruiting bodies, supporting its potential as a functional food ingredient. Despite lower total glucan, crude fiber, and amino acid levels, mycelium presents a promising alternative for nutritional enrichment, warranting further optimization. This study integrates agro-industrial byproducts to produce nutrient-dense food, supporting sustainable systems and plant-based alternatives aligned with global food security goals, paving the way for large-scale production and further optimization.